Pick shaft snubber



Aug 9, 1949, F. G. LAKE ET AL PICK SHAFT SNUBBER Filed July 16, 1947 d M 6 W ATTORNEY Patented Aug. 9, 1949 UNITED STATES TENT OFFICE PICK SHAFT SNUBBER M. W. Keliogg Company, corporation of Delaware Jersey City, N. J., a

Application July 16, 1947, Serial No. 761,380

The present invention relates to a pick shaft snubber for fly shuttle looms.

The conventional loom picking mechanism comprises a pick cam shaft, a pick cam thereon, and. a pick cam follower riding on said pick cam and mounted on a pick arm of a bell crank affixed to a pick shaft. The other pick arm of the bell crank has a connection with one end of a lug stick. The other end of the lug stick is connected to a lug strap adapted to engage the picker stick and throw it at the proper time for pickmg.

The toe section of the pick cam which serves to draw the picker stick inwardly towards the loom, rises abruptly, and as a result, imparts to the cam follower sufficient momentum to overthrow said follower substantially radially outwardly beyond the peak of said cam toe section and out of contact with the active surface of said cam.

One object of the present invention is to provide a new and improved pick shaft snubber which checks the overthrow of said pick shaft with a minimum of shock and strain on the loom parts.

Another object is to provide a new and improved pick shaft snubber which, while it permits the normal overthrow movement of the pick shaft, applies the checking load at such a distance from the center of the pick shaft that the checking load necessary is comparatively small and the distance through which the checking load is effective is much greater than usual so that the checking action is smooth and with minimum of shock effect on the loom parts.

.As a feature of the present invention, the pick shaft snubber comprises a substantially upright snubber leaf spring secured at its lower end near the base of the loom, and adapted to be pressed at its upper free end during overthrow movement of the pick shaft by one of the pick arms of the bell crank secured to said pick shaft. The checking impact of the bell crank arm during its overthrow movement is thereby transmitted through the snubber directly to the base portion of the loom where said loom is most rigid and stable, thereby reducing shock vibrations resulting from checking action to a minimum.

Various other objects, features and advantages of the invention will be apparent from the following particular description, and from an in- 3 Claims. (Cl. 139 -147) spection of the accompanying drawing, in which:

' Fig. 1 is a front elevation of a portion of the picking mechanism on the right side of the loom,

showing a pick shaft snubber embodying the pres- I taken on line 2--2 of Fig. 1.

The drawings show only the right side of the loom, but it must be understood that the picking .motion and pick shaft snubber on the left side 'of the loom are of similar construction. The

loom is shown provided with two loom sides Ill, each comprising two spaced parallel vertical frame webs I I and I2 interconnected and braced as indicated in copending application Serial No. 691,237, filed August 17, 1946. The two frame webs H and I2 of each loomside may carry the bearings l3 and M for a rocker shaft l5, to which the lower end of a lay supporting sword I6 is secured.

Only part of the picking mechanism is shown, since this in itself forms no part of the present invention, and may be of the conventional type.

. The parts of the picking mechanism not shown comprise in general a picker stick, at the foot of Which is the parallel motion for moving the picker at the upper end of the stick parallel to the race plate. The picker stick is propelled in its picking movement'by an arrangement comprising a pick cam secured to a cam shaft which may constitute the main cam shaft, as in the case of a conventional m, or may be a separate pick cam shaft.

Engaging the pick cam is a pick cam follower supported on a pick arm 20 of the bell crank 2|. The'other pick arm 23 has a connection at its outer end with one end of a lug stick or rod 24. The other end of the lug stick 24 is connected to 3, lug strap (not shown) adapted to engage the picker stick (not shown) and throw it at the proper time for picking. Pick arms 20 and 23 i are affixed to a hub 26 which is keyed to the pick shaft 22. V

' The pick arm 23 1's shown comprising a long split sleeve 25 and provided with a pair of clamping flanges 21 on opposite sides of its split. In the sleeve 25 is an extension rod 28, which is adjustable therein to permit adjustments in the effective length of the pick arm 23, and which can 3 be locked in adjusted position therein by means of the bolts 30 passing through the clamping flanges 21.

In the operation of the picking mechanism so far described, as the pick cam rotates, the cam follower engages the upper section of said cam. The pick cam periphery has a toe or projecting part which rises suddenly, and which serves to impart to the cam follower the necessary impetus to rotate the pick shaft 22 clockwise (Fig. 1), and to throw thereby the picker stick inwardly towards th e-loom; 'Ihemomentum impartedto the cam follower during this camming'action. is'so great, as to cause said cam follower to be lifted radially outwardly beyond the peak of the cam toe.

In order to check the pick shaft in its overthrow movement, there is provided a snubber comprising an upstanding leaf spring 35 secured at,its lower end to a region of the-loomframe near the base, and free at its upper end to be engaged and thereby be flexed during the overthrow movement of the pick arm 23. For anchoring the lower base end 36 of the leaf spring 35, there is provided a bracket 3 secured on the outer side ofthe inner frame webJZ near the base of the looin by studs'f38,and having'a groove or chan- "Iielll forreceiving said base spring end. .The 'le af spring 351s removably but firmly retained in "the groove-cs by means of a dog 4|, and screw members {52 passing through said dog and" 7 through said leaf spring.""A resilient, pad,' not shown, of rubber or similarmaterial may be" interposed betweenthe base spring end 36 and dog -and/orbe tweenthe basespring end 36'and the 1 1 acl'iet 3; 1" to provide amounting of desired resil- *fi encyiorth'e basespring end 36.

1% The'leaf' -spiing 35 desirably tapers upwardly from its base section36' to afford substantial rigiditynear' the'bas'e section where the' greatest beriding str'esss' are setup during checking acbr, and whichhas tapering sides to conform with the tapering sides of the leaf spring; The part es is secured to the leaf spring 35by' fasten- ;ing members '46,'which'may-take the form of ;bolts -orrivets-passing through respective holes insaid pad and with their heads confined" in countersunk holes. s

The snubber spring 35 is shown in Fig. 1 in relaxed positionand at the instant when the bell crank 2 I has reached its maximum picking speed, and is beginning its overthrow movement. In this unstressed. position of the snubber spring 35, said spring will b e arched and'will extend genemn fin' an oblique direction upwardly and to- "wards the outer side of the loom towards the pick arm 23. I

In the unstressed position of the snubber spring 'sfifshown in full lines in Fig. 1, the outer face of the wear pad 4 5 for a substantial part of its iendlength will be parallel to the longitudinal side o"f"the pick arm 23; and will be in position shown to e' engagedby' said arm as the cam follower 'i eac'hes the" peak ofthe cam toe and the picker stick reachesits shuttle delivery position. In "thismaxiinum speed position ofthe pick mechanism, the pick shaft 22 is rotating clockwise (Fig. 1")?and"the" momenturnof the parts is carrying lthe pick arm 23 past this position. As the pick "airm' 23 continues its clockwise overthrow movement, it stresses'the' leaf snubber spring '35 back so that this spring reacts to take up the shock iopening through which the stick passes.

4 of the parts of the pick mechanism and checks the movement of the pick shaft 22.

The picker stick is also desirably checked during its overthrow movement by a picker stick snubber (not shown). The picker stick snubber begins its checking action a short time after the picker stick has reached its maximum speed or shuttle delivery position. However, the pick shaft snubber begins to act before then at the instant the pick shaft 22 reaches maximum speed. This serves to delay the lug strap with relation to the picker stick during the'initial overthrow period, so that thestick moves relative to the lug strap to take up the clearance in the strap From then .on, the lug strap and the picker stick move .the wear on said pad will be substantially uniform. Also, the relative slide movement between the pad .and the pick arm 23 will be at a minimum duringoverthrow checking action, so

. ,thatsaid pad will be subjected to a minimum of abrasive wear action.

,By anchoring the snubber spring 35 near the base of the loom, shocks due to the checking ac- ;tion of the spring will be transmitted to the most rigid and stable section of the loom. Therefore,

no excessive shocks or vibrations incidental to this checking action are set up in the loom.

. By employing a snubber spring 35 having a comparatively long leverage arm and by imposing thecheckingload adjacent the end of pick arms .23, the pick shaft 22 is permitted to rotate ,through its normal overthrow movement before it is completely arrested so that the checking action is gradual and smooth and excessive shocks and vibrations are not set up in the shaft 22 ,aridthe elements associated therewith. Also, by

this arrangement the checking load applied is v,much less than in theprior arrangementswherein the checking load is applied near the shaft end of .the cam follower pick arm.

While theinvention has been described with particular reference to a specific embodiment, it .is to be understood that it is not to be limited ,cated in position to be stressed during overthrow movementof said shaft by a member carried by saidfshaft to check said movement.

2. In a loom of the fly shuttle type, a pick shaft,"a pick arm secured to said pick shaft, and

.a"si1ubber for said pick shaft comprising a leaf spring arched in unstressed condition and mount- .ed at its lower end with its concave side facing the outer side of the loom, said spring extending generally obliquely upwardly and outwardly with respect to .the loom and towards said pick arm, and'being located-in position to be stressed by said pick arm during overthrow movement of said pick arm to check said movement.

3. In a loom of the fly shuttle type, a loomside comprising a vertical frame web, a pick shaft, a pick arm secured to said shaft and having a connection to a picker stick; and a snubber for said shaft comprising an upstanding leaf spring, means for removably mounting the lower end of said spring to said. frame web near the base of the loom, and a wear pad of shock-absorbing material secured to the upper end of said spring, said spring being located in position to cause said wear pad to be engaged by said pick arm during overthrow movement of said pick arm to check said movement.

FRANCIS GERARD LAKE. ELVIN A. MASTRIANI.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

